If the dicor is the self leveling type normally used on the roof, it won't work on vertical surfaces.
My experience with the factory applied caulking is it's crap. I had to redo my roof the first year and the Dicor self levelling I used lasted almost 4 years in comparison.Proflex and sikflex is what the higher end and even the factory uses. It is good stuff.
You can't go wrong with Dicor, but I like Proflex. Proflex seems harder to work with (it's really sticky when wet) but I think it lasts a lot longer.
Any silicone will be hard to remove.